SQL & PL/SQL :: Initialize Variable With Whole Array

I'm having some hard times with attempts to initialize a set of values, Of a specific column from a table into a variable containing it as an array(like a single column table).

I've created & populated table TEST_TAB:

SQL>
SQL> CREATE TABLE "TEST_TAB"
2 ( "KEY1" NUMBER(10));

Table created.

SQL>
SQL> insert into "TEST_TAB" values ('1');

1 row created.

SQL> insert into "TEST_TAB" values ('2');

1 row created.

SQL> insert into "TEST_TAB" values ('3');

1 row created.

SQL> insert into "TEST_TAB" values ('4');

1 row created.

SQL> commit;

Commit complete.

SQL>
SQL>

Then I am trying to compile a function that gets a parameter - a number. The function should check whether this number exists in this list(return 1), or not(return 0).

I want to initialize key1 column of table TEST_TAB *into* v_my_array(this will be my list), just to see that I can have a set of values in this variable. Then I will want to see if the number is in that list, and return 1 or 0 accordingly.

I get the following error compiling, and can't seem to understand what's wrong:

SQL> create or replace function is_num_in_list (p_number number)
2 return number
3 is
4 TYPE varray_type IS TABLE OF NUMBER(10) INDEX BY PLS_INTEGER;
5 v_my_array varray_type;
6 begin
7 select key1 into v_my_array from TEST_TAB;
8 --if the number provided exists in the list, then 1(TRUE)
9 if p_number in v_my_array then
10 return(1);
11 else
12 --if the number provided *IS NOT* in the list, then 0(FALSE)
13 return(0);
14 end if;
15 end;
16 /

Warning: Function created with compilation errors.

SQL> show error
Errors for FUNCTION IS_NUM_IN_LIST:

LINE/COL ERROR
-------- -----------------------------------------------------------------
9/16 PLS-00103: Encountered the symbol "V_MY_ARRAY" when expecting one
of the following:
(
SQL>